Re: [Xenomai-help] How to make main sleep ? clock_nanosleep ? rt_alarm_wait ?

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

Lionel Perrin wrote:
 > I got some difficulties to use either rt_alarm_wait or clock_nanosleep.
 > It seems i haven't understood what's a "context that can sleep".
 > 
 > First of all, what do we need to use clock_nanosleep ?
 > Is it impossible to use this function in the main thread ?

Xenomai clock_nanosleep, nanosleep or rt_alarm_wait services are
reserved to Xenomai real-time threads, and will return an error of EPERM
otherwise.

If you want a non-realtime sleep, you may still access standard services
using __real_nanosleep or __real_clock_nanosleep.

If you want to obtain a Xenomai real-time thread using the posix skin
you have to make it use the SCHED_FIFO policy, either by creating it
with the pthread_create service, specifying non null creation attributes
or by changing the scheduling policy of an existing thread with
the pthread_setschedparam service.

If you want to obtain a Xenomai real-time thread using the native skin,
you may create it with the rt_task_create service or turn an existing
thread into a real-time thread with the rt_task_shadow service.

 > (...)
 >     ret = nanosleep(&tp, &rmtp);
 >     switch (errno) {
 > (...)

errno value is only meaningful if nanosleep returns -1. In particular it
is not garanteed to be zero if nanosleep did not fail.

-- 


					    Gilles Chanteperdrix.